Rajaratnam gained $36 million from insider trading

Federal prosecutors said they will file fresh charges against Sri Lankan-born hedge fund operator Raj Rajaratnam alleging he made at least $36 million from the biggest insider trading case in US history, double what was previously thought.

"The government now has evidence that Rajaratnam's illicit gains yielded profits that were at least twice as large as those previously alleged," Assistant US Attorney Joshua Klein wrote in a court filing.

Rajaratnam's profits in the schemes, described as the largest insider trading case in the history of US, were about $36 million, the prosecutors said. Earlier, the investigators said Rajaratnam, 52, got $17 million from the broad insider trading scheme.

In October, Galleon Group LLC founder Rajaratnam was charged in one of the country's largest insider-trading case. Galleon Group is a hedge fund with up to $7 billion in assets under management.

He received 12 charges, four counts of conspiracy and eight counts of security fraud. "People will probably ask just how pervasive is insider trading these days? Is this just the tip of the iceberg?" Preet Bharara, the US attorney for the Southern District of New York, had said previously, adding "We aim to find out."